Yesterday, I filed a flight plan from KPSP to KSAN. I fly the 737 800. It takes at least a half hour to load up a chosen flight plan into this bird. I've flown about a hand full of times on PE and when asking for IFR clearance on my filed plan, I've always received back what I filed for the most part except on yesterdays KPSP to KSAN flight.

When it came time to ask for clearance on my filed KPSP THRM6 TRM BARET5, the controller cleared me to a completely different route. Instead, I was instructed to KPSP CATERDRAL1 DEP V514 DCT MZB. I understand this can happen in real life. Not a problem. But when I was being read the new route, I was taken by surprise and tripped all over myself when I had to read the route back to him. An ego crusher for sure!

My questions are:

1. Given that I fly the 737 which has a complex FMS (Flight Management System), should I not even bother choosing my own route and just file a blank route? Should I just ask for clearance and take what I am given instead? That way, I can save time by not pre-programming the flight system and I can focus on what the controller will give me when its clearance instruction time? Re-constructing a flight plan into your FMS is not very fun when it is not even close to what you filed.

2. Any tips on how to prepare for a controllers read back for flight plan clearance. I usually employ CRAFT and fill in the blanks as he/she speaks the route to me. They have a very tough job, and I’d like to try to not make it harder.

The vast majority of people are getting a SID, then TRM V514 MZB, consistent with what the controller gave you.

There's a very simple solution to your issue, and that would be to NOT program your FMC until you've picked up your clearance. There is no operational advantage to programming the FMS before you've obtained your actual clearance.

It's more efficient to file a route (particularly one that people have been getting in busy terminal areas such as Socal) rather than filing direct because you will NEVER get direct in a complex airspace like socal, which means you'll end up with a full route clearance every time (if you try to file direct), which takes up a lot of radio time.

Instead, file a route that is known to be good, and you should get something close to 'as filed.' THEN program the FMC.

Also, learning to read back clearances containing routes other than what you filed is an really important skill. It's not a bad thing that you got exposed to it.

First, CRAFT is a good method of preparing for your clearance delivery. But, if the controller throws you a curve ball or fast ball, there is no shame in asking for them to repeat your clearance.

Second, become familiar and proficient with your FMS, which will happen through practice and repetition. This will help you when changes need to be made, especially during busier times of flight. In the real world weather, traffic sequencing, and airport configuration can cause changes to your planned runway, route, and SIDs/STARs.

To echo Scott... With practice it shouldn't take more than a couple minutes, often times mere seconds, to fully/partial change your route in the B737. Even when airborne this will be a normal occurrence in the r/w. The more you use it and fly the aircraft the better you will become. In fact, it generally takes me under 5 mins to fully preflight the FMC on the B737. Granted I have been using the B737 in the sim for 7+ years.

Try watching some others (who are proficient with using the systems) stream on twitch.com or check out some YouTube videos on using the FMS. Here are a couple of people I would recommend to follow on twitch who's streams can be educational.https://www.twitch.tv/blackbox711 PE user and R/W A320 Pilothttps://www.twitch.tv/avgeek1 Doesn't use PE, but hes a R/W ATC'er at ATL Approach and always will take the time to explain on stream what he's doing and why.https://www.twitch.tv/cirrusmax PE user and R/W insturment pilot. He flies a variety of aircraft in the simulator.https://www.twitch.tv/joshgibbs PE user and R/W pilot from the SAN area.

All of those guys streams will be entertaining and most of the time educational if you're just getting started.